Professor Alan Brichta

Alan Brichta

Professor Alan Brichta's primary research interest is balance and the vestibular
system. His most recent NHMRC-funded research has focused on the
efferent branch of the vestibular system – the pathway by which the
brain can modulate inner ear sensitivity.

Despite fifty years of
ongoing research, the functional purpose of the efferent vestibular
system still remains a mystery – most likely due to its inherently
complex mechanisms of action. To combat this, Alan has developed a
semi-intact model of the vestibular system, which allows for faithful,
high-resolution recordings of hair cell function. This recording
technique has provided new information about the efferent vestibular
system, with particular regards to the novel alpha-9 nicotinic receptor.

Alan has ongoing collaborations with vestibular experts Dr
Americo Migliaccio (Neuroscience Research Australia; NeuRA), Dr
Joseph Holt (University of Rochester, USA) and Dr Richard Rabbitt (University of Utah, USA), as well as HMRI
neuroscientists Professor Bob Callister and Dr Doug Smith. He is also
closely affiliated with the Garnett Passe and Rodney Williams Memorial
Foundation (GPRWMF), and the Neuro-Otology Society of Australia
(NOTSA). Alan is currently the Head of Discipline (Anatomy),
supervises multiple PhD students, and teaches into a number of programs
including Bachelor of Medicine and Bachelor of Biomedical Science.

What intrigues you most about the vestibular system?

I
know it may sound a little strange but almost from the moment I learned
about the vestibular system, I've been fascinated and intrigued by the
subtle and mysterious way it works to provide us with a sense of
balance.

The vestibular system allows us go about our
daily activities, correcting almost every move we make, so that we don't
fall over. And it does this with little or no fanfare or even very much
recognition. The vestibular system is neither blatant nor does it
intrude on our consciousness with the flamboyance of primary senses such
as vision and hearing. If the vestibular system is doing its job
properly it is almost imperceptible, working away with exquisite
precision, speed, and accuracy. Perhaps it is precisely this 'backstage
activity' that is responsible for our general lack of awareness and why
we know so much less about this system in comparison to its close
cousin, the hearing or auditory system. In short, the more I get to know
the vestibular system the more I am in awe of the 'no nonsense' way in
which it influences almost all aspects of our lives, making it the
'quiet achiever', or dare I say, the unsung hero or heroine of the
central nervous system.

Career Summary

Biography

Alan Brichta is a neurobiologist with research interests in the anatomy and physiology of peripheral and central vestibular system. In particular, his studies have focused on vestibular hair cells and their associated primary afferents and has recently developed an isolated preparation of the mouse inner ear to study these unusual cellular components. This approach allows stable, high-resolution, intracellular recordings whilst the tissue undergoes near 'natural' (mechanical), rather than artificial (electrical) stimulation. Results from these studies are helping us understand the cellular mechanisms underlying normal and abnormal function associated with the peripheral vestibular apparatus. In addition, Dr. Brichta is studying vestibular nucleus neurons in the brainstem that are the major recipients of transmitted vestibular organ output. These regions are thought to be highly modifiable and may prove to be ideal targets for rational therapeutic strategies aimed at treating balance disorders. Dr. Brichta was awarded a prestigious five year Garnett Passe and Rodney Williams Memorial Foundation Senior/Principal Research Fellowship.

Administrative ExpertiseFormer member of Academic Senate and Faculty Board during a period of major change in teaching and learning at the University. Attracted significant equipment funding to the EM /X-Ray Unit by successfully applying for ARC-LEIF grant. Submission of Anatomy discipline Roadmap for Medical School Accreditation Committee. Contributed to the development of the new Bachelor of Podiatry Program. Provided Biomedical Science input with regard to course provisions and assessment of background course pre-requisites. Member of Faculty Library Committee during a difficult fiscal period that resulted in significant cuts in printed journal subscriptions. Member of NHMRC Grant Review Panel. External Ph.D. Examiner of Ph.D candidates.

CollaborationsIn addition to his own studies on the vestibular system, Dr. Brichta has had a long-term collaboration with his good friend and colleague, Dr. Bob Callister. Together they have had over thirty years of collaborative efforts on sensory and motors systems.

Qualifications

PhD, Ohio University - USA

Bachelor of Science (Anatomy), University of New South Wales

Keywords

Anatomy

Electrophysiology

Neuroscience

Spinal Cord

Vestibular system

Fields of Research

Code

Description

Percentage

110903

Central Nervous System

30

110905

Peripheral Nervous System

20

110906

Sensory Systems

50

Professional Experience

UON Appointment

Title

Organisation / Department

Professor

University of NewcastleSchool of Biomedical Sciences and PharmacyAustralia

Academic appointment

Dates

Title

Organisation / Department

1/07/2008 - 1/06/2013

Senior/Principal Research Fellowship

Garnett Passe and Rodney Williams Memorial Foundation

University of NewcastleSchool of Biomedical Sciences and PharmacyAustralia

1/07/2007 -

A/Prof.

University of NewcastleSchool of Biomedical Sciences and PharmacyAustralia

1/11/1998 - 1/12/2000

Lecturer

University of NewcastleSchool of Biomedical Sciences and PharmacyAustralia

1/07/1995 - 1/10/1998

Assistant Professor

University of Chicago, Chicago, IllinoisPhysiological and Pharmacological SciencesUnited States

Membership

Dates

Title

Organisation / Department

1/01/2014 -

Membership - ARO International Committee

ARO International CommitteeAustralia

1/01/2014 -

Membership - NHMRC Assigners Academy Committee

NHMRC CommitteeAustralia

1/01/2011 - 31/12/2013

Membership - NHMRC Committee

NHMRC (National Health & Medical Research Council)

Invitations

Participant

Year

Title / Rationale

2012

A Question of Balance: The best-laid schemes o' mice an' menOrganisation: The Royal Society of Medicine, London
Description:
Much of what we have learned about the human body has come not from direct observations but has been inferred from animal studies. Fortunately, as we have learned from the human and other genome projects, we are almost genetically identical to chimpanzees and remarkably similar to mice. Sequencing of the mouse genome for example, completed in late 2002, estimates a gene count of 23,786 and for comparison, humans are estimated to have 23,686 genes â a hundred fewer! Therefore, it can be argued that what we learn in mice is applicable to humans.
This assertion is most likely true when it comes to ancient and evolutionarily conservative sensory systems such as the peripheral vestibular system. To date, however, its residence deep within the hardest bone of the skull (making it neither easy to access nor convenient to manipulate) has hampered our study of the vestibular organs of the inner ear. To overcome this significant technical obstacle we have developed a surgically isolated inner ear of the mouse. This preparation allows us unprecedented access to the workings of the organs of balance. Indeed, using our isolated in vitro preparation and altering the volume of inner ear fluid by only a few nano-litres we have observed anomalous neuronal activity that may contribute to the symptoms of Meniereâs disease. By stripping the isolated inner ear preparation still further, (like layers in an onion) but carefully preserving the important and unique micro-architectural features of the individual organs, we have discovered a novel way in which the important motion detectors of the vestibular system (hair cells) communicate with their closely associated nerve afferent nerves. These results would have been difficult if not impossible to obtain without semi-intact preparations of vestibular organs.
Despite these notable advances one must acknowledge that these results are from a very small mammal that weighs four orders of magnitude less than an adult human (7 grams vs. 70 kilograms). Therefore, are any of these findings relevant to humans? To address this fundamental issue we have begun to isolate viable inner ears from post-mortem human foetal tissue (10 to 18 weeks gestation). This means we can now apply some of the techniques we have learned using mice to in vitro human vestibular tissue. The preliminary results are promising. We are able to record activity from foetal hair cells and nerve terminals up to 8 hours after the tissue arrives in the laboratory. Our data suggest the human peripheral vestibular system is fully functional midway through the second trimester and indeed resembles a 3 week old, fully weaned, postnatal mouse.
Taken together, these various approaches provide us with new insights into basic machinery of the peripheral balance organs in humans. Our ultimate goal is to have the findings from these animal and foetal models translated into targeted clinical therapeutics. For example, due to pathological increases in endolymph volume, we believe the membranous labyrinth is distended causing abnormal and confusing signals to the brain. Alleviating these volume changes by pharmacological and/or surgical intervention would eliminate distensions and accompanying vertiginous attacks. Similarly, based on our new understanding of the key role potassium plays in vestibular organ function, particularly between hair cells and primary afferents, suggests this ion is tightly regulated to ensure normal balance function. Thus a focus on restoration and maintenance of potassium in the inner ear would be a clinical requirement. In short, our continued hope is that better basic understanding leads to targeted diagnostic and therapeutic strategies for treating the debilitating effects of balance disorders.

HÃ¼bner PP, Lim R, Brichta AM, Migliaccio AA, 'Glycine Receptor Deficiency and Its Effect on the Horizontal Vestibulo-ocular Reflex: a Study on the SPD1J Mouse', Journal of the Association for Research in Otolaryngology, 14 249-259 (2013) [C1]

Lee H-Y, Callister RJ, Brichta AM, 'Morphophysiology of Vestibular Afferents Recorded from an In Vitro Preparation of the Mouse Inner Ear', Abstracts of the Twenty-Fourth Annual Midwinter Research Meeting of the Association for Research in Otolaryngology, 0 124 (2001) [C3]

Callister RJ, Brichta AM, Graham BA, 'Beyond the dorsal horn: The use of animal models to discover new sites for pain therapy', Australian and New Zealand Journal of Psychiatry, Newcastle, NSW (2008) [E3]